Eventum is an open-source web-based issue management and tracking system from MySQL AB. It runs on PHP with a MySQL backend (of course), and offers a rich featureset and easy installation - in theory.
Eventum is a little bit picky about it's installation environment. Attempting to install Eventum on a default installation of Apache (with MySQL libraries installed) results in some bad luck. When you load the installer, you'll get a long list of files that Apache doesn't have the permission to write to. Then, it'll tell you you're missing the GD2 library, and that you need to turn on the deprecated allow_call_time_pass_reference in php.ini.
Under Windows, installing GD2 means uncommenting one line in php.ini. Under Linux, it means gathering libjpeg, libpng, and libttf, and gd2, compiling all of them, then reconfiguring and recompiling PHP itself. Easy for some, but hey, I'm not a comand-line ninja. That stuff takes me a while.
Once you've done your bowing and scraping, the installation is rather straightforward - fill in the fields, click the button, it installs itself, but doesn't log you in or tell you the default account - you have to go back to the INSTALL file to get the default admin account, and use this to create your own account and other accounts. Then you're ready to get started.
Once you've got it installed, you have to create your project. This seems simple enough until you try to create a ticket, only to discover that new projects have no default priority codes or issue types - an odd choice.
The interface leaves much to be desired, even for a developer's tool. In terms of usability, it isn't very intuitive in general, and navigation can be complex and confusing. The entire interface could sorely use a severe overhaul - something I may take on if I decide to continue using it.
Eventum is very feature-rich, which is a bad thing in my situation. I chose it for its quick install, not for the features; I just need issue management, not timekeeping, which seems to play a large part in Eventum. I also don't need all the pie charts and graphs that made GD2 necessary in the first place.
As far as it's core featureset is concerned, it is an effective issue manager, though some features are clunky. For example, the notes on issues are difficult to get to; as a developer, I want to be able to open an issue and immediately see the note history so I can see where progress is being made and what the current status is, beyond the "implementation" status code.
It should really also open to the My Assignments page if you have assignments, rather than the Stats page. It also sorely needs a preference to let you change the default rows per page on the issue lists to something other than 5 (yes, the default is 5, and each row actually only takes up one line on the page. I'm not sure what they were thinking.)
I'm stuck with Eventum for the time being as I don't have time to find, install and migrate to an alternative. I chose Eventum as a quick-fix. Once I have time to apply to the issue of issue management, I may switch to another solution, or try to fix Eventum. I'll burn that bridge when I get to it - who knows, maybe it'll have grown on my by then. Or maybe I'll finally make that issue management system I keep putting off...